From 3b07a15fd12d5452bf539cd855edde8139db1686 Mon Sep 17 00:00:00 2001
From: Amine Najahi <mohaminaj@gmail.com>
Date: Sun, 6 Oct 2013 14:43:16 +0200
Subject: [PATCH] Detect usage of incomplete types inside struct/union

Make sure the only exception is for a flexible array member
as the last element of a structure
---
 tccgen.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/tccgen.c b/tccgen.c
index d5b915b..bab4f7c 100644
--- a/tccgen.c
+++ b/tccgen.c
@@ -2740,7 +2740,7 @@ static void parse_attribute(AttributeDef *ad)
 /* enum/struct/union declaration. u is either VT_ENUM or VT_STRUCT */
 static void struct_decl(CType *type, int u, int tdef)
 {
-    int a, v, size, align, maxalign, c, offset;
+    int a, v, size, align, maxalign, c, offset, flexible;
     int bit_size, bit_pos, bsize, bt, lbit_pos, prevbt;
     Sym *s, *ss, *ass, **ps;
     AttributeDef ad;
@@ -2814,9 +2814,13 @@ static void struct_decl(CType *type, int u, int tdef)
             prevbt = VT_INT;
             bit_pos = 0;
             offset = 0;
+            flexible = 0;
             while (tok != '}') {
                 parse_btype(&btype, &ad);
                 while (1) {
+		    if (flexible)
+		        tcc_error("flexible array member '%s' not at the end of struct",
+                              get_tok_str(v, NULL));
                     bit_size = -1;
                     v = 0;
                     type1 = btype;
@@ -2824,6 +2828,13 @@ static void struct_decl(CType *type, int u, int tdef)
                         type_decl(&type1, &ad, &v, TYPE_DIRECT | TYPE_ABSTRACT);
                         if (v == 0 && (type1.t & VT_BTYPE) != VT_STRUCT)
                             expect("identifier");
+                        if (type_size(&type1, &align) < 0) {
+			    if ((a == TOK_STRUCT) && (type1.t & VT_ARRAY) && c)
+			        flexible = 1;
+			    else
+			        tcc_error("field '%s' has incomplete type",
+                                      get_tok_str(v, NULL));
+                        }
                         if ((type1.t & VT_BTYPE) == VT_FUNC ||
                             (type1.t & (VT_TYPEDEF | VT_STATIC | VT_EXTERN | VT_INLINE)))
                             tcc_error("invalid type for '%s'",